Energy, Sound and Light: Grade 4 Study Guide
Energy makes things move, glow, heat up and make sounds. It can change form but is never used up.
Energy is the ability to cause change. It comes in forms such as motion (kinetic), sound, light, heat and electrical energy. The faster an object moves, the more motion energy it has. When objects collide, energy moves from one object to another and may also change into sound and heat.
Energy is transferred (moves from place to place) and transformed (changes form). A battery-powered torch changes stored chemical energy into electrical energy and then light and a little heat.
Forms of energy
| Form | Example | Detected by |
|---|---|---|
| Motion | a rolling ball | it moves other objects |
| Sound | a drum beat | vibrations felt and heard |
| Light | the Sun, a lamp | we see it |
| Heat | a hot cup | temperature rises |
| Electrical | a lit bulb in a circuit | it powers devices |
Sound and light
Sound is made by vibrations that travel as waves through air, liquids or solids. Light travels in straight lines and can be reflected (bounced) off a mirror, refracted (bent) through water or a lens, or blocked to form a shadow. We see an object when light from it reaches our eyes.
Pluck a rubber band.
Feel it and hear the sound.
A tighter band gives a higher pitch.
Faster vibrations make a higher sound.
Simple electric circuits
A circuit needs a source (a battery), wires and a load (a bulb), joined in a complete loop. If there is a break, such as an open switch, no current flows. Conductors like metal let electricity pass; insulators like plastic, rubber and wood do not. Never experiment with mains electricity; use batteries only.
Worked example and common misconceptions
Example: A ball rolls down a ramp and hits a block. Gravitational stored energy changes into motion energy, which moves the block and also makes a small sound and a bit of heat. Common misconceptions: energy gets 'used up' (it changes form instead), and light 'travels from our eyes'. Design a fair test by changing only one thing at a time, such as the height of the ramp.
Check your understanding: model answers
1. Electrical energy changes into heat and light. 2. An object blocks the light, which travels in straight lines. 3. For example, copper wire is a conductor and rubber is an insulator.
✨ Key Takeaways
- Energy causes change and can change form.
- Sound comes from vibrations.
- Light travels in straight lines and can reflect or bend.
- A circuit must be a complete loop.
💬 Questions for Discussion & Reflection
- Name two energy changes that happen when a toaster is used.
- Why does a shadow form?
- Name a conductor and an insulator.
Print a science observation log →